Pump



` n+1-onu PUMP Filed Juno 1. 1926 June 7, 1927.

INVEN TOR.

A TTORNEY.

Patented June 7, 1927.

PATENT oF-Flc.

` HENRYFORD, oF DEARBORN, MICHIGAN.

Y PUMP.

Application med :rune 1,

The object of my invention is to provide improvements in pumps of simple, durable and inexpensive construction.

Al further object of my invention is to provide a pump adapted to create a partial vacuum and which yeliminates valves having moving parts or moving parts'for the oper'- ation of the valves inl so far as is possible.

A further object of my invention is to provide a pump adapted to create a partial vacuum and which is especially adapted to be used in connection with an Vinternal combustion engine and to be operated by one of the shafts thereof.

Still a further object of my. invention is to provide a vacuum creating pump designed to be mov-ed in one direction by a cam and to be -moved in the opposite direction by a spring so that the moving parts may be as simple as possible and as effective. i y

)Vith these and other objects in view, my invention consists in the arrangement, construction, and combination ofthe various parts of my improved pump as described in the specilication, claimed in the claims, and illustrated in the accompanying drawings, in which:

Figure (1), shows a vertical, central, sectional, longitudinal yview through my improved pump, some of the parts associated therewith being shown in dotted lines.

Figure (2),shows a vertical, transverse, sectional view, taken on the line 2-2, -of Figure u 1 a Figure (3), shows a vertical, transverse, sectional view, taken on the line 3 3, of Figure l lFigure (4), shows. an end -viewof the pump, the cam mechanism forfoperating same being in the foreground.

Figures (5), (6), (71), and (s), am dia-7 grammatic views illustrating respectively 'the position of the pump during the intake stroke, the intake proper, thefcompression stroke, and the exhaust.

Referring to the accompanying drawings, I have illustrated portions of an `internal combustion engine suchyfor instance, as a crankcase thereof, by the reference numeral the crankcase being provided with bosses i (11) designed to receive tappets (12), which are actuated by'cams on a camshaft (13). The parts just described are of ordinary construction in connection with 1926. se'r1a1 No. 112,762.

internal combustion engines and especially those of the automotive type.

lThe housing (10) is provided with an opening (14) designed to have the flanges (15) of vthe'pumphousing (16) bolted or otherwise securedfthereto for the purpose of making a liquid tight joint between the housing (16) and the housing (10) yand for forming the support Yfor my improved pump. A substantially,` cylindrical member (17) is rigidly secure-d within the housing (16) in any suitable manner but inthe form of device here shown this isvaccomplished by swagi'ng in the outer edges of the housing (16v) asat (18)` around a contracted portion'of the member 17) whereby a rigid and liquid tight connection is formed. This cylindrical member (17 is provided adjarcentto its outer end with a threaded opening (19), which'terminates in a passageway (20)* which extends axially vthrough the member (17) from the opening (19) to 'position at about the center of the member (17). At the inner end ofthe passageway (20) atransverse passageway (21) is formed in .the member (17), whereby the opening (19) and the passageways (20) and `(21) may together form a continuous vpassageway from.v the exterior of the pump to a position at about the center thereof. These passageways and the opening I shall here-k inafter generally refer to as an intake port.

'At the `opposite end of the member (17) is anl axial passageway (22), which extends from the inner end of the member (17) along ber (24) 1 shall hereafter call the piston of my improved pump. It is provided adjacent to the inner end thereof with an annular flange (25), whichis designed to form a shoulderagainst which a coil spring (26) maybean The housing (16) adjacent to the pistonl (24) is of substantially greater -diameter than said piston, whereby this coil spring (26) may be housed 1 between` the housing (16) and the piston (24), and thereby the tendency of the/spring (26) to expand will tend to force the piston (24) olf from the member (17) or inwardly. An odset or shoulder (27) adjacent'to the outer end of the member (17) forms a stop for the outer end of this spring to enable it to accomplish its function.

A plurality of outlet ports (29) are formed' in vertical alignment at intervals in the piston (24), and at a position aligned substantially with the passageway (23) in the member (17) when the piston is in its outer posi tion, as illustrated in Figure (1) and Figurev (8). rlhe interior of the piston (24) may be formed with an annular groove (30) adjacent to these outlet ports (29) to aid in the discharge of the compressed air from my improved pump. Aplurality of compression retaining expansion rings (31) may be disposed inv appropriate grooves in the member (17) for the purpose of rendering my improved pump more eilicient should it be desired' In the form of device here illustra-ted I have shown one of these rings (31) adjacent to the outer end of the piston (24) and one adjacent tothe inner or closed end thereof.

The'camshaft is provided with a cam (32), which is designed to bear against the closed endl of the piston (24) for the purpose of actuating the pistonv in one direction,

that is outwardly.

In the practical operation of my improved vacuum creating pump, it will` be understood that this pump is especially designedto be used in connection with the fue-l supply system of an internal combustion engine of the type wherein a partial vacuum is used to draw the fuel from a fuel supply tank toa second tank which furnishes a reservior from which the fuel may feed by gravity to the carburetor of the engine. This pump is designed to furnish the necessary partial vacuum and is connected into the fuelsupply system at the place where a vacuum is necessary by any suitable fitting which ymay be connected with the threaded opening lThen the engine is operating of course, the

camshaft will rotate, thereby rotating the cam 32). Movement of the cam (32) to the position shown in Figure (1) and Figure (8) will move the piston (24) toits outer position against the pressure of the spring (26) and further rotation of the shaft (153-) will move the cam (32) out of the path of the piston (24) so that the spring (26) will force the piston inwardly. As soon as the pist-on (24) has moved a distance equal to the width of the passageway (23) the exhaust ports will be closed by the movement of the piston and a partial vacuum will be created in the space between the inner end of the member (17') and the closed endv of the piston 24), as may be seen by referring 'to' Figure' (5) adjacentV to the reference nu- Ineral (33).. As the piston (24) continues its outward movement to the full amount, this vacuum creating chamber (33) will eX- pand until the piston reaches the position illustrated in Figure (6). At this point, ends of an'el'ongated annular groove (34) in the inner wall of the piston (24) will come due to the actuation of the shaft (13), the

space becomes'smaller as the cam during the second. halt'. of its revolution tends to pressthe piston (24) outwardly. As soon as the `piston (24) travels a distance equal toy the width of the passageway (23.), communication between the chamber (33) and the inlet pert is closed and any air in the chamber (33) becomes compressed by the movement of the pistonv (24), thisl compression increasing as the chamber diminishes, until the piston reaches substantially the position shown in Figure (8), at which time this chamber has practically no dimensions, as the closed end of the piston (24') comes almost into contactl with the end of the memberI (17). Just prior to the time that the piston (24) reaches this position, however, the-exhaust ports (29) and the pis ton (24) come opposite the passageway (23), thereby permitting the air from the chamber (33), which'is under compression, to escape down the passageway (22)- and out through the passageway (23) and exhaust ports (29). Further rotation of the cam merely ca-uses a cycle of the events just described to be repeated, whereby the parts connected with the inlet opening ('19) ,will be eifected by a substantially constant partial vacuum. v

Many advantages arise from the use ofmy improved vacuum creatingpump in that the `ordinary construction ofv an internal combusion engine need be altered only in; two ways to have this pump ,z namely, by pro viding the mount-ing open-ing (14) inthe crankcase and by adding an additional cam (32) on the cam shaft (13). The mounting of the pump is readily accomplished by merely removing or replacing the bolts or screws holding the flange (1:5) Vto the crankcase. The piston itself is actuated inI one direction by the cam and in the other directionv by the spring', se that complicated or expensive moving parts are largely eliminated: and; wear is largely compensated. for automatically. No additional moving parts for the valves or the valve actuations are required, so that the device is extremely ,simple and not at all likely to become clooeed with, da @iV ai@ like. if the device shiaa become clogged, the moving parts, namely,

the piston (24.-) and spring (26) may be readily removed to accomplish the necessary cleaning, and the various passages are all in such shape that theymay be readily cleaned. It should also be noted that the partial vacuum created by this pump will remain substantially constant relative to the. engine speed, so that the fuel supply will be governed by the engine speed rather than by the partial vacuum created by the intake of the engine itself.

Some changes may be made in the arrangement and construction'of the various parts of my improved device without departing from the. spirit of my invention, and it is my intention to cover by the following claims such changes as may be reasonably included within the scope thereof.

I claim as my invention.

l. ln a pump for creating` a pai-tial vacuum, a member having an inlet port therein and a passageway .therethrough adjacent to the end thereof opposite the inlet port, a cup shaped piston member mounted on the Erst described'member, said piston member having exhaust ports therein and a recess designed to permit communication between the inlet port and the passageway in the first described member when the piston is in one of its positions, and means for reciprocating said piston.

Q. In a pump for creating a partial vacuum, a. member having an inlet port therein and a passageway therethrough adjacent to the end thereof opposite the inlet port, a cup shaped piston member mounted on the first described member, said piston member having exhaust ports therein and a recess designed to permit communication between tlie inlet port and the passageway in the first described member when the piston is in one of its positions, a cam device adapted to move said piston in one direction, and

resilient means for urging said piston in the opposite direction.

3. In a partial vacuum creating device adapted to be associated with an internal combustion engine having a crankcase and a camshaft, a cam formed on said camshaft, a pump housing mounted on said crankcase housing, a substantially cylindrical member fixed in said housing, a cup shaped piston member mounted on saidcylindrical member for reciprocation, said piston being adapted to be moved in one direction by the said cam, a spring mounted within said housing and adapted to move said piston in the opposite direction, and means for operatively Aconnecting said cylindrical member and piston, including passageways formed within said piston and cylindrical member whereby reciprocation of the piston will create a partial vacuum.

4. ln a pump a substantially `cup shaped housing member, a substantially cylindrical member fixed within said housing meinbei', said cylindrical member having a plurality of passageways therethrough, designed to form an intake port and a second passageway, a cup shaped piston mounted r for reciprocation on said cylindrical member, said cup shaped piston having an exhaust port therein and a recess designed in one position of the piston -to permit communication between the inlet port and passageway in the cylindrical member, a spring mounted between the piston and the housing, designed to yieldingly urge the piston in one direction of its movement, and means for positively urging the piston in the opposite direction of its movement.

Signed at Dearborn, in the county of lVayne, State of Michigan, this th day of May, 1926.

.HENRY FORD. 

